1. Field of the Invention
The present invention relates to a handy printing device capable of automatically forming images on a print medium when manually or automatically scanned across the surface of the print medium.
2. Description of the Related Art
A variety of printers, such as, dot impact, ink jet type printers, are known in the art. These printers normally stationary, that is, they are meant to be used in single location. Such printers include: a reciprocally moving carriage mounted with a thermal head or an ink jet head; and a sheet-feed mechanism, such as a platen, for moving a print sheet in a sheet-feed direction that is perpendicular to the reciprocal scan direction of the carriage. Printing is performed by reciprocally scanning the carriage across the surface of the print sheet while synchronously driving the sheet-feed mechanism. However, such stationary printers can only be used to print on cut-sheets or special continuous sheets and can not be used to print on oddly shaped sheets or notebooks, for example.
British Patent No. 1366253 discloses a handy printing device without a carriage or a sheet-feed mechanism. The disclosed printing device is manually scanned across a print medium. A movement amount detection unit detects relative positional change between the print head of the print device and a print medium and outputs a detection signal accordingly. To perform printing, a control portion drives the print head in synchronization with the detection signal from the movement amount detection unit. The handy printing device of British Patent No. 1366253 enables printing at any position on a variety of different types of printing medium, such as thick bound books or notebooks, print sheets with unusually large dimensions, or other printing medium that can not be used in stationary printers.